Diaphragm controlled air relief valve

ABSTRACT

A valve for venting of air from the pumping chamber of a liquid pumping system. The valve assembly includes a valve casing having a through chamber with a valve seat and a valve head which is normally maintained on the downstream side of the valve seat in spaced relation therefrom and which is connected to a valve stem extending through the valve seat. A flexible diaphragm is attached to the valve stem on the upstream side of the valve seat. Under low pressure, low volume flow or no flow conditions the valve remains in open position. As the flow rate increases, increased pressure on the diaphragm forces the valve stem in the upstream direction, bringing the valve head into closing contact with the valve seat.

FOREIGN PATENTS OR APPLICATIONS 19,537 10/1934 Australia ..l37/505.l3

0 United States Patent 1 1 11 1 3,730,215 Conery et al. 51 May 1, 1973 1DIAPHRAGM CONTROLLED AIR 1' 90,775 4/1959 Netherlands. .......137/505.13RELIEF VALVE 904,624 2/1954 Germany ..137/50s.13 85,677 2/1936 Sweden..l37/505.l3 [75] lnvenwrsl Wllllam cmery; Donald Kaes' 140,790 2/1935Austria ..137/505.13 both of Ashland, 01110 946,700 8/1956 Germany..251/54 [73] Assignee: Hydr-O-Matic Pump Company,

Hayesville, Ohio Primary Examiner--l-Ienry T. Klinksiek AssistantExaminer-Robert J. Miller [221 8,1971 Attorney-Oldham & Oldham [21]Appl. No.: 132,422

[57] ABSTRACT [52] US. Cl. ..l37/494, l37/505.13, 251/54 A valve forventing of air from the pumping chamber [51] Int. Cl. ..G05d 16/00 of aliquid pumping system. The valve assembly in' [58] Field of Search137/494, 484.2, 484.4, cludes a valve casing having a through chamberwith a 137/498, 505.46, 505.13; 417/299, 311. 302; valve seat and avalve head which is normally main- 251/45, 36, 48 tained on thedownstream side of the valve seat in spaced relation therefrom and whichis connected to a [56] References Cited valve stem extending through thevalve seat. A flexible UNn-ED STATES PATENTS diaphragm is attached tothe valve stem on the upstream side of the valve seat. Under lowpressure, low Heldeman X volume flow or no flow conditions the valveremains 2'l89'75O 2/1940 Barge "13750513 X in open position. As the flowrate increases, increased pressure on the diaphragm forces the valvestem in the 929,007 7/1909 phmipsm "251/48 upstream d1rect10n, brmgmgthe valve head mto clos- 9s4,s74 2 191 1 Winton... ..251 54 x mg Contactwith the valve Seat- 2,526,972 10/1950 Ray ..l37/505.l3 X

3 Claims, 3 Drawing Figures Patented May l, 1973 v 3,130,215

INVENTORS WILLIAM J.CONERY Y DONALD A. KAESSEN W fw z ATTORNEYS.

DIAPHRAGM CONTROLLED AIR RELIEF VALVE In impeller type pumps, thepresence of air in the pumping chamber can prevent priming of the pump.This is especially true when the pump must operate against a substantialback pressure. In such situations some means must be provided to ventthe air from the pump chamber. These means may include manuallycontrolled valves or externally controlled automatic valves. Sucharrangements are inefficient as they require either the presence of anoperator or a control system.

It is the primary object of the present invention to provide an airrelief valve for a pump which valve is automatic in its operation andwhich is self-contained, requiring no external control.

It is also an object of the invention to provide an air relief valvewhich provides reliable operation.

. Another object of the invention is a provision of an air relief valvefor a pumping system which valve is of a simple and trouble free design.

Yet another object of the invention is a provision of an air reliefvalve for a pumping system in which the operating pressure level of thevalve may be adjusted without requiring the disassembly of the valvestructure.

The above and other objects and advantages of the invention which willbecome apparent in the following detailed description are achieved byproviding an air relief valve assembly which consists, essentially, of avalve housing having inlet and outlet ports and a circu lar valve seatintermediate said ports, a valve head adapted to have sealing engagementwith the valve seat, a valve stem extending from the head through theregion of the valve seat, spring means for normally urging the valvestem and valve head into an open relation relative to the valve seat,and a flexible diaphragm connected to the valve housing and to the valvestem to move the valve stem and valve head upon increased pressure tobring the valve head into sealing engagement with the valve seat. I

For a more complete understanding of the invention and the objects andadvantages thereof reference should be had to the following detaileddescription and the accompanying drawings wherein there is shown apreferred embodiment of the invention.

In the drawings:

FIG. 1 is a schematic side elevational view ofa sump pump arrangementemploying the air relief valve of the present invention;

FIG. 2 is a sectional view of the air relief valve of the presentinvention, showing the valve in its open position; and

FIG. 3 is a view similar to that of FIG. 2 but showing the valve in itsclosed position.

One of the uses of the air relief valve of the present invention is inconjunction with a sump pumping arrangement such as may be used in asewage system. Such an arrangement is designated generally by thereference numeral of FIG. I and includes a sump 12 which serves tocollect sewage or other liquid. An impeller type pump 14 driven by amotor 16 has an inlet 18 for drawing liquid from the sump. The pump 14may be supported in any suitable manner. The pump discharges the liquidthrough a discharge pipe 20 which may, for example, be connected to adischarge main 21 of a sewage system. The system includes a check valve22 to prevent the reverse flow of sewage or other liquid from the main2] into the sump 12. The motor is operated by suitable controls, notshown, which may consist of a level actuated switch which starts themotor 16 whenever the liquid level in the sump rises above apredetermined upper limit and stops the motor 16 whenever the liquidlevel drops below a predetermined lower limit. In the event the pumpingchamber of the pump 14 becomes fully or partially filled with air whenthe pump is not operating, the pump will not be self priming when it isnext started up. The combination of the check valve 22 and the pressurein the main 21 produce substantial back pressure on the discharge line20 of the pump 14 to prevent the expulsion of the air entrapped in thepumping chamber. In order to overcome this difficulty the presentinvention provides an air relief valve 24 which is connected by asuitable auxiliary conduit 26 operatively connected to the dischargeport of the pump 14. The valve may be provided with a discharge pipe 28for returning any fluid passing through the valve 24 to the sump 12. Aswill be explained in more detail below, the valve 24 is normally openand remains open until the pump output pressure rises above a certainlevel. Thus, the valve 24 permits the pump 14 to begin operating withlittle or no back pressure and thus permits the complete venting of anyair from the pumping chamber.

The air relief valve 24 of the present invention is illustrated in FIGS.2 and 3. A valve casing 30 has inlet and outlet ports 32 and 34,respectively, and a through chamber 35 connecting the inlet and outletports. Intermediate the inlet and outlet ports the walls of the valvecasing 30 define an annular valve seat 36. A valve head 38 is carried bya stem 40 and adapted to be brought into and out of engagement with theannular valve seat 36 to close or open the through passage 35 of thevalve casing 30. As can be seen from the drawings, the valve stem 40extends axially through the valve seat region 36 and includes an upperstem portion 42. The upper portion 42 of the valve stem 40 is slidablyreceived in a housing 44 which is secured to the valve casing 30. The

housing 44 includes a cylindrical bore 46 and a piston 48 is affixed tothe upper end of the valve stem portion 42 and is slidably received inthe bore 46. A coil spring 50 is provided between the piston 48 and aretaining block 52 slidably carried in the cap 53 sealing the upper endof the bore 36. This spring serves to bias the piston 48, valve stem 40,42 and valve head 38 downwardly into the open position, as is shown in FIG. 2. Preferably, an adjustment screw 54 is provided in the end cap 53for regulating the position of the retaining block 52 and, hence, theamount of downward pressure exerted on the valve stem assembly by thecoil spring 50. t

A flexible diaphragm 56 has its periphery secured between the valvecasing 30 and the flanges 58 of the housing 44, the bolts or screws 59which secure the housing 44 to the casing 30 serving to clamp the blediaphragm 56 and the housing 44 is preferably filled with oil. The bore66 in the housing 44 through which the upper valve stem portion 42extends is of slightly greater diameter than the diameter of the valvestem portion 42 so that a small passage is provided for the oil in thechamber 64. Likewise, the piston 48 is of a slightly smaller diameterthan the bore 46 to provide a passage 64 permitting the flow of oilaround the sides of the piston 48.

" also increases and, when this pressure becomes sufficient to overcomethe spring 50, the flexible diaphragm forces the valve stem assembly 40,42 upwardly, bringing the valve head 38 into engagement with the valveseat 36 to block flow through the valve. As the diaphragm 56 is forcedupwardly, the oil in the chamber 64 is forced through the bore 66surrounding the upper valve stem portion 42. The viscosity of the oiland the amount of clearance between the upper valve stem portion 42 andthe bore 66 determine the rate at which the oil flows upwardly from thechamber 64 to the bore 46. This arrangement provides a delaying actionfor the valve closing, a typical delay being from /2 to 1 minute.

When the valve 24 is employed in the pumping system of FIG. 1,- thevalve will be in its open position when the pump is not operating sincethere is no pressure in the conduit 26 or the inlet portion 32. As thepump begins operation, fluid flow will be primarily through the conduit26 since the check valve 22 and thepressure in the main 21 will provideback pressure in the pump discharge line 20. Thus, the initial flow fromthe pump 14 is through the valve 24 and the pipe 28 to return to thesump. This is an open path with little back pressure and, as a result,the pump 14 is able to discharge any air which may have become entrappedin the pumping chamber. As the pump continues operating, pressure in theconduit'26 increases causing the valve 24 to gradually close. The timedelay of the valve assures that closing does not occur until asufficient time has been allowed to fully vent any air from the chamberof the pump 14. During subsequent operation of the pump, the valve 24 isheld closed by the pressure on the diaphragm 56 and the pump dischargesthrough the discharge pipe 20, check valve 22 and discharge main 21.When the pump 14 is stopped the valve 24 again opens as the coil spring50 is no longer opposed by fluid pressure transmitted through thediaphragm 56. The dashpot arrangement comprised of the bore 46, piston48, bore 66 and chamber 64 again serves to I control the rate of actionof the valve. The dashpot arrangement further serves to prevent thevalve from opening or closing as a result of rapid pump output pressurefluctuations.

The valve head 38 is secured to the stem 42 as by a capscrew 39 whichsecures the washers 60 and 62 between the ends of the stem and valvehead and against the dia hragm 56. A slightleakage path may be providedto al ow pressure decay in a completely tight pumping system to removethe pressure from the diaphragm 56 nd allow the valve to open when thepump 14 is stopped. This can be achieved in several well known ways ashaving the valve head 38 slightly smaller than its annular seat or bore36, or if the valve head 38 is larger than its annular seat 36, a smallslot may be provided across the seating surface of either or both parts.

It will be understood that while only the best known embodiment of theinvention has been described and illustrated in detail herein, theinvention is not limited thereby or thereto. Reference should thereforebe had to the appended claims in determining the true scope of theinvention.

What is claimed is:

1. An air relief valve for a pumping system, comprismg:

a valve casing having inlet and outlet ports connected by a throughchamber;

a valve seat on the walls of the through chamber and intermediate theinlet and outlet ports;

a valve stem slidably received in a first bore in the valve casing onthe upstream side of the valve seat, the valve stem extending throughthe region of the valve seat;

a valve head on the end of the valve stem extending through the regionof the valve seat, the valve head being adapted to have sealingengagement with the valve seat to close the through chamber;

biasing means for urging the valve stem and valve head in the downstreamdirection to normally hold the valve head away from the valve seat;

a flexible diaphragm secured to the valve casing and to the valve stemat a point intermediate the first bore and the valve head, the diaphragmdividing the through chamber into a first region communicating with thefirst bore only and a second region communicating with the inlet andoutlet ports and extending across the valve seat; and

the casing being provided with a second bore axially aligned with andcommunicating with the first bore butof greater diameter than the firstbore, the end of the second bore opposite the first bore being closed,the valve stem extending into the second bore, and a piston beingconnected to the end. of the valve stem within the second bore, thefirst region of the casing chamber and the bores being substantiallyfilled with oil, sufficient clearance being provided between the valvestem and first bore and between the piston and the second bore to permitoil flow at a controlled rate.

2. The air relief valve according to claim 1 wherein the biasing meanscomprises a coil spring acting between the closed end of the second boreand the end of the valve stem extending into the second bore.

3. The air relief vvalve according to claim 2 further includingadjustment means carried by the closed end of the second bore forvarying the force applied-by the spring to the valve stem.

1. An air relief valve for a pumping system, comprising: a valve casinghaving inlet and outlet ports connected by a through chamber; a valveseat on the walls of the through chamber and intermediate the inlet andoutlet ports; a valve stem slidably received in a first bore in thevalve casing on the upstream side of the valve seat, the valve stemextending through the region of the valve seat; a valve head on the endof the valve stem extending through the region of the valve seat, thevalve head being adapted to have sealing engagement with the valve seatto close the through chamber; biasing means for urging the valve stemand valve head in the downstream direction to normally hold the valvehead away from the valve seat; a flexible diaphragm secured to the valvecasing and to the valve stem at a point intermediate the first bore andthe valve head, the diaphragm dividing the through chamber into a firstregion communicating with the first bore only and a second regioncommunicating with the inlet and outlet ports and extending across thevalve seat; and the casing being provided with a second bore axiallyaligned with and communicating with the first bore but of greaterdiameter than the first bore, the end of the second bore opposite thefirst bore being closed, the valve stem extending into the second bore,and a piston being connected to the end of the valve stem within thesecond bore, the first region of the casing chamber and the bores beingsubstantially filled with oil, sufficient clearance being providedbetween the valve stem and first bore and between the piston and thesecond bore to permit oil flow at a controlled rate.
 2. The air reliefvalve according to claim 1 wherein the biasing means comprises a coilspring acting between the closed end of the second bore and the end ofthe valve stem extending into the second bore.
 3. The air relief valveaccording to claim 2 further including adjustment means carried by theclosed end of the second bore for varying the force applied by thespring to the valve stem.